powerline interference
 

I read that powerline interference will often times diminish when it rains.
This is presumably due to loose hardware becoming temporarily tightened when
moisture causes the utility pole to swell. Well, in my case the noise
substantially worsens and becomes more broadband during periods of rain. Can
anyone explain a possible reason for this? The RFI guy from the local
utility company seems confident that work scheduled for next week in my
neighborhood will correct the problem. I certainly hope this is the case.
Maybe then I can finally hear some dx. Wish me luck.


Brian

Brian wrote:

I read that powerline interference will often times diminish when it rains.
This is presumably due to loose hardware becoming temporarily tightened when
moisture causes the utility pole to swell. Well, in my case the noise
substantially worsens and becomes more broadband during periods of rain. Can
anyone explain a possible reason for this? The RFI guy from the local
utility company seems confident that work scheduled for next week in my
neighborhood will correct the problem. I certainly hope this is the case.
Maybe then I can finally hear some dx. Wish me luck.

Good luck. The local utility here (city owned) is pretty good at figuring out
interference problems. Due to my complaints years ago they went out and
purchased the RF sniffing equipment needed to track down the offending
hardware.

Have had very good luck with them since.

Steve
Holland, MI
Drake R7, R8 and R8B

http://www.iserv.net/~n8kdv/dxpage.htm

Rain usually washes off the dust that collects on insulators and causes arcing
during foggy or humid weather. But if a carbon path has developed on an
insulator, rain will worsen the problem.

Bill, K5BY

Brian thought it a good use of my time to say:
I read that powerline interference will often times diminish when it rains.
This is presumably due to loose hardware becoming temporarily tightened when
moisture causes the utility pole to swell Well, in my case the noise
substantially worsens and becomes more broadband during periods of rain. Can
anyone explain a possible reason for this? The RFI guy from the local
utility company seems confident that work scheduled for next week in my
neighborhood will correct the problem. I certainly hope this is the case.
Maybe then I can finally hear some dx. Wish me luck.

Well, rain is an attenuator. Perhaps the signal you are looking for is
being attenuated by the rain, and, that attenuation plus the noise generated
by the power lines=lower SNR.

I see it all the time(not in SW bands, I am in Satellite
Communications[8GHz], but the theory has to be the same) Rain attenuates
desired signal, lowering C/Kt

Sysiphus wrote in :

Well, rain is an attenuator. Perhaps the signal you are looking for is
being attenuated by the rain, and, that attenuation plus the noise
generated by the power lines=lower SNR.

I see it all the time(not in SW bands, I am in Satellite
Communications[8GHz], but the theory has to be the same) Rain attenuates
desired signal, lowering C/Kt



True, but the effect of rain on LF and HF signals are negligible. This has to
do with the significantly longer wave lengths of the LF/HF signals especaily
when compared to that of microwave. As the wave length of the signal
approaches the size of the rain drops, attenuation increases.

Take a look here :

http://www.telesat.ca/satellites/tra...ttenuation.htm


--
Panzer

Sysiphus wrote:




Well, rain is an attenuator. Perhaps the signal you are looking for is
being attenuated by the rain, and, that attenuation plus the noise generated
by the power lines=lower SNR.

I see it all the time(not in SW bands, I am in Satellite
Communications[8GHz], but the theory has to be the same) Rain attenuates
desired signal, lowering C/Kt

At 8GH OK, but not at the frequencies generated by powerline arcing in
the HF spectrum.